383 nm Laser system (T-MOT)

The 383 nm laser system consists of 767 nm lasers which are then frequency doubled to achieve 383 nm light.

External Cavity Diode Laser (ECDL)

For 767 nm lasers, ECDL in Littrow configuration is used. Typically we used the laser diodes from Eagleyard Photonics: EYP-RWE-0790-02000-1500-SOT02-0000

Recently, Eagleyard has replaced these with new laser diodes: EYP-RWE-0760-02010-1500-SOT12-0000

TA

Output Power: 1.5 W

Input Current: 2 A

Injection Power: 32 mW

Power behind 30dB Isolator: 1.05 W

Originally this TA was used: EYP-TPA-0765-01500-3006-CMT03-0000. Is this still true?

Fiber

PMC-780-5,0-NA012-3-APC-200-P

Incoupling: 67%

Power behind fiber: 700 mW

Frequenzy doubling

LBO-Crystal

Lenght: 15 mm

AR coating

Resonator

Ring resonator (double Z configuration)

Length: 280mm

Curvature of mirrors: 50 mm (S3 and S4)

Distance of mirrors: 64 mm

Waist: 30µm (crystal), 130µm (long arm)

Transmission: TS3 = 0.049%, T1 = 1.2 %

Conversion efficiency ENL = 6.1*10^(-5)/W

Linear losses: eL = 0.85(0.15) %

Finesse: F = 270

Stabilisation

PDH-Method

Error signal at about 20 MHz

Stabilisation: Laser 4 - Potassium

Dopplerfree Saturation Spectroscopy on D1 line of Potassium:

1st the two beams with similar intensity are generated by the beam sampler and are send trough the glas cell

one part of the initial beam is going trough the sampler to a double pass aom and then in the other direction trough the glas cell, crossing only one beam. Important: the beam coming from the aom must have a much higher intensity!

the first two beams, coming from the sampler trough the cell are than monitored by the PD. The signal is substracted